Sheets made of 100% cotton are generally regarded as providing the greatest comfort and absorbency. Nevertheless, the durability of the sheet is an important consideration, especially in regard to commercial applications, where the sheet may be subjected to high temperatures and harsh chemicals during laundering and ironing. For example, the life cycle of a 100% cotton sheet is approximately 50 to 60 industrial launderings and ironings. Since many applications require that the sheets be changed every day, such as in hospitals and hotels, the replacement cost of sheets is a significant expense.
One solution has been to replace cotton fiber with polyester fiber in sheeting fabric. While the use of polyester fiber significantly increases the durability of the sheet, the comfort level of the sheet in terms of hand and absorbency suffers.
Heiman, U.S. Pat. No. 5,495,874 discloses a woven fabric useful for sheeting having cotton warp yarns and continuous filament, textured, polyester filling (weft) yarns. The product has a warp-to-fill ratio of from 1.6:1 to 2.2:1. Despite having a relatively high warp-to-fill yarn ratio, the fabric is substantially weaker in the warp direction than the filling direction, with reported tensile strength values of 57.4 lbs. and 99.0 lbs., respectively. The relatively low tensile strength in the warp direction represents a “weak link” in the fabric construction, and likely point of failure during the life cycle of a sheet made from the fabric.
There remains a need in the industry for a sheeting fabric having the comfort of cotton fiber and the strength and durability of polyester fiber. Further, there is a need for a sheeting fabric having a relatively high tensile strength in both the warp and filling direction. Still further, there is a need for a sheeting fabric having a tensile strength in the warp and filling direction that is balanced, to avoid over-engineering the fabric in one direction, at the expense of the tensile strength in the cross direction.